Thionyl Chloride → HCID 172035639, compound

Participants

Reaction Steps

The carboxylic acid from example 3 (10.0 g, 16.89 mmol) was dissolved in dry dichloromethane (450 ml) and thionyl chloride (2.742, 20.27 mmole) was added together with 10 drops of N,N-dimethylformamide. The mixture was refluxed with stirring for 4 hours under nitrogen and the solvent and excess thionyl chloride were removed in vacuo. Fresh dichloromethane (500 ml) was added and the freshly ground anhydrous aluminium chloride (7.88 g, 59.1 mmole, 3.5 equiv.) was added in three portions (over 20 minutes) at room temperature whilst under nitrogen. After a further 30 minutes the supernatant was separated from the brown oil which separated and 2M hydrochloric acid was added (250 ml). Trituration afforded a white solid which was partitioned between water and dichloromethane. Evaporation of the dried organic phase afforded crude title compound which after silica gel chromatography gave 2.68 g (35%) of material identical with that previously described in European Pat. No. 34,004.

Provenance & Evidence